This invention relates to a wireless (termed herein as xe2x80x9cradioxe2x80x9d) portable information terminal transmitting/receiving system. More particularly, it relates to a radio data transmitting/receiving system used with advantage for data transmission/reception between a radio portable information terminal and an information network center.
Recently, a portable information terminal device for mobile computing has become popular, while radio portable information terminals, comprised of the portable information terminal device and the wireless (radio) communication function attached to the portable information terminal device, is also used extensively. This radio portable information terminal is connected for communication with the information network center via a radio base station connected to a public network, and includes a WWW (world wide web) server, supervising the WWW information, or an E-mail server, in order to exchange the information with the information network center connected to the Internet (see for example to FIG. 1).
In this case, a user of the radio portable information terminal checks the indication of the residual cell capacity on a display unit of the radio portable information terminal or the state of intensity of the electrical field displayed with an antenna mark to ready for data reception.
If the PUSH type information distribution is to be made from the information network center to the radio portable information terminal, data is distributed to the radio portable information terminal while it is unknown whether or not the radio portable information terminal is ready for reception. If, in such case, the reception is not possible on the side of the radio portable information terminal due to, for example, battery power off, the result is wasteful data re-transmission.
As discussed above, the conventional radio portable information terminal system has the following inconveniences:
The first problem is that the user has to perform the operation of checking the residual capacity of the battery displayed on a display unit of the radio portable information terminal or the state of the intensity of the electrical field displayed as an antenna mark and of receiving the data from the radio portable information terminal to the information network center, each time the data is received, thus complicating the operation.
The second problem is that, when the PUSH type information distribution is to be made from the information network center to the radio portable information terminal, data distribution is done even though it is not known whether or not the radio portable information terminal is readied for receiving the information, such that, if the battery capacity is short, the electrical field is weak or the terminal is outside the service range and hence the radio portable information terminal cannot receive the information, the result is wasteful data transmission and re-transmission.
The reason is that, when the PUSH type information distributionistobe made from theinformation network center to the radio portable information terminal, the information network center is not provided with functional means adapted for grasping whether or not the radio portable information terminal is in a state readied for reception.
In view of the above-mentioned problems of the prior art, it is an object of the present invention to provide a radio portable information terminal data transmitting system in which there is no necessity of carrying out the operation of confirming the battery capacity/shortage or the intensity of the receiving electrical field, which has so far been felt to be necessary in data communication/reception with the information network center.
It is another object of the present invention to provide a radio portable information terminal system in which the state of the radio portable information terminal can be recognized on the information network center side even when the PUSH type information distribution is to be made from the information network center to the radio portable information terminal.
For accomplishing the above object, the present invention provides a radio data transfer system of a radio portable information terminal wherein, when the radio portable information terminal effects data transmission/reception via a radio base station with an information network center, the radio portable information terminal detects the current battery capacity level and the receiving electrical field level to compare and verify whether or not said levels are sufficient to permit said data transmission/reception; if the current battery capacity level and the receiving electrical field level are on the transmission/reception enabling level, the radio portable information terminal formulates a data transmission/reception enabling signal to send the data transmission/reception enabling signal via the radio base station to the information network center; and wherein the information network center checks to see that the radio portable information terminal is in the transmission/reception enabling state to effect data transmission/reception with the radio portable information terminal.